Tuning fork



Oct. 15, 1968 T. E.A MYERS TUNING FORK Filed Dec. 14, 196e uuml J 3,405,589 TUNING FORK Thomas E. Myers, Rte. 1, Box 560, St. Charles, Ill. 60174 Filed Dec. 14, 1966, Ser. No. 601,607

Claims. (Cl. 84-457) ABSTRACT OF THE DISCLOSURE least one additional tine proportioned and sized to vibrate at a second frequency.

This invention is in the field of tuning forks and more particularly is concerned with a multiple tine fork having three, four, five, or more tines, with one or more of such tines detuned from the fundamental tone of the tuning fork.

Generally, the audible tones produced by musical instruments such as the bell or chime are comprised of a fundamental frequency and various overtone harmonics thereof. The interesting, distinguishing and enjoyable tone quality of such musical instruments is produced by and is a function of the number of overtone harmonics present and their respective intensities. Accordingly, depending on the number and intensity of harmonic overtones present,

,various tone qualities such as a mellow, crisp, or golden tone are produced.

When a tuning fork is excited into motion, the tuning fork tines vibrate at their resonant frequency. The sound Wave produced by such a tuning fork is sinusoidal and comprises one frequency corresponding to the tine resonant vibration frequency. Accordingly, the classical two tine tuning fork produces an uninteresting and sterile sound unlike the musical sounds produced'by instruments such as the bell or chime.

NA primary object, therefore, of this invention is a tuning fork which when excited into motion produces an interesting tone such as that of a bell, chime, or other like instrument.

Another object is a, tuning fork which, when excited into movement,emits a sound having a frequency sepctrum comprising more than one frequency.

Another object is a tuning fork having at least three tines, with one of such tines detuned from the other two so as to produce a different tone.

Another object is a tuning fork with at least one regeneration tine which tends to sustain the fork in vibratory motion for a longer period of time.

Another object is a tuning fork having improved tone quality.

Another object is a tuning fork, which emits consonant harmonic sounds.

Another object is a tuning fork which emits a sound which comprises a fundamental frequency and various harmonics thereof.

Another object is a tuning fork which produces multiple tones such as the triad C, E, and G.

Another object is a tuning fork having at least three tines, with one of such tines tuned slightly at or sharp so as to produce a beat having a frequency such that a vibrator tremolo is produced.

Other objects will appear from time to time in the ensuing specification, claims and drawings in which:

FIGURE 1 is an elevational view of an exemplary form of the tuning fork of this invention;

United States VPatent O 3,405,589 Patented vOct. 15, 1968 ICC FIGURE 2 is an elevational view of a variation of the Vtuning fork of FIGURE 1;

FIGURE 3 is an end view of the tuning fork of FIG- URE 2;

4FIGURE 4 is a partial elevational view of a further variation of the tuning fork of FIGURE l;

FIGURE 5 is an end view of the tuning fork of FIG- URE 4;

FIGURE 6 is a partial elevational View of a further variation of the tuning fork of FIGURE 1;'and

FIGURE 7 is a partial elevational view of another exemplary form of the tuning fork of this invention.

Like reference numerals will be used to refer to like parts throughout the following ldescription of the drawings.

In FIGURE l, the tuning fork is shown as comprising two fundamental tines 10 and 12 symmetrically rdisposed about a third tine 14. Tines 10 and 12 are of equal length and cross-section so that both such tines have the same resonant vibration frequency and, therefore, when excited into movement, will generate the same audible tone. Tine 14 is depicted as being shorter than tines 10 and 12 so that such tine will have a higher resonant vibration frequency and generate a higher pitched tone than that of tines 10 and 12.

The tines 10, 12 and 14 are shown as being integrally connected to the cross member 16. Supporting means, such as a handle 18, may be provided to mount or support the tuning fork.

The third tine may be variously shaped, it being important only that such tine has a resonant frequency and tone different from that of the fundamental tines 10 and 12. Detuning, the third tine from the fundamental tines may be accomplished by variously altering the shape of such third tine. For example, generally, the stiffer the tine the higher the vibration frequency and tone and the taller the tine the lower the vibration frequency tone. Accordingly, the third tine may be detuned from the fundamental tines 10 and 12 by merely reducing its size in one plane such as tine 20 of FIGURES 2 and 3; or, by reducing the cross-section of the tine at its fixed end, as at 22 in FIG- URE 4; or, by enlarging the tine cross-section at its fixed end relative to the cross-section at its free end as at 24 in FIGURE 6. y

In FIGURE 7, another variation of the tuning fork of this invention is shown as having four tines 26, 28, 30 and 32. Tines 26 and 32 are generally symmetrically disposed about detuned tines 28 and 30 and are identically sized so that they will vibrate at the same fundamental resonant frequency and thereby produce the same tone. Tine-28 is reduced in height from that of fundamental tines 26 and 32 so that it will vibrate at a higher resonant frequency and thereby produce a higher pitched tone than that of the fundamental tone produced by tines 26 and 32. Tine 30 is shown as being further reduced in height from tine 28 so that it will have a resonant vibration frequency higher than that of tine 28 and therefore will produce a higher pitched tone than that of tine 28 or fundamental tines 26 and 32.

The use, operation and function of this invention are as follows:

The tuning fork of this invention may be used in a variety of musical instruments. For example, a plurality of multi-tine forks may be incorporated in an electric organ or carolon, with such forks tuned or voiced so as to simulate a set of chimes. Further, a plurality of multi-tine tuning forks could be incorporated in an instrument, with such forks tuned or voiced to simulate instruments such as the bells, glockenspiel or Vibraphone. It should be readily apparent, that the tuning fork of this invention may be utilized in a variety of musical instruments.

In application, the tuning fork of this invention may be excited into motion by a variety of means. For example, the tines may be struck electrically using a solenoid or they may be struck manually with, for example, with a quil or padded hammer. The sound produced by the tuning forks may be picked up electrically and amplified thereby permitting use of the instrument in applications such as churches and the like. i

Although tuning forks having three and four tines respectively have been depicted and described, it should be understood that the tuning fork of this invention may consist of any number of tines greater than three. For example, the tuning fork of this invention may consist of five, six, seven or more tines. The important aspect of the invention is, however, that at least one of the tines be detuned from the fundamental frequency of the tuning fork. Itis preferable that the fundamental tines, such as tines l and 12 in FIGURE 1 and tines 26 and 32 in FIGURE 7, be outermost and generally symmetrically disposed about the center detuned tine'or tines. If general symmetry is `not maintained, the tuning fork becomes unbalanced and optimum performance is lost.

The detuned tine or tines, such as tines 28 and 30 of FIGURE 7, may be detuned from the fundamental frequency by varying the tine geometry in a number of ways. The detuned tine or tines may be made to vibrate at a frequency above or below that of the fundamental tines. The degree of difference between the fundamental frequency and detuned frequencies may be varied to any desired degree. Accordingly, by varying the number of detuned tines and their respective frequencies, the tuning Ifork of this invention may be voiced to simulate many desired instruments or sounds. For example, the four pronged fork of FIGURE 7 may be voiced to produce the harmonic triad comprising notes C, E, and G; or, the detuned tines 28 and 30 may be structurally formed to produce various overtone harmonics of the fundamental frequency produced by tines 26 and 32. Although tuning forks having only two tines producing the fundamental tone and no more than one detuned tine producing any particular detuned tone have been described and depicted, it should be understood that more than two tines may be used in producing the fundamental tone and there may be more than one tine producing a detuned tone. Accordingly, in simulating the tone quality of various instruments, overtone harmonics may be produced in various intensities relative to the intensity of the fundamental frequency.

One advantage of the multi-tine tuning fork of this invention is that the presence of the extra tines gives rise to more sympathetic driving motion which will sustain the tuning fork in vibration for a longer period of time.

The primary advantage of the tuning fork of this invention is that it provides an accurate, compact, simple structure, which when once tuned does not require returning, for accurately reproducing sounds of othermusical instruments, such as a chime or bells, or for creating new interesting and enjoyable sounds.

Whereas the preferred form of the invention has been shown and described herein, it should be realized that there are many modifications, substitutions and alterations thereto within the scope of the following claims.

I claim: y

1. A tuning fork comprising at least fthree substantially parallel tines joined to integral connective and supporting means, with at least two such tines proportionedl and sized to vibrate at a rst resonant frequency and at least one such tine proportioned and sized to vibratevat a second resonant frequency when said tuning fork is eXcitedfinto movement, thereby producing a sound having a frequency spectrum comprising at least two` frequencies, said first mentioned two tines being symmetrically .positioned around said one tine to drive the latter in regenerative manner. .i

2. The structure of claim 1 further characterized in that said second resonant frequency differs `from said first resonant frequency by a fraction of a step in a given musical scale to produce a beat sound (one cycle per second).

3. The structure of claim 1 further characterized in that said second resonant frequency differs from said lirst resonant frequency by an integral number of musical scale steps to produce a harmonious sound (at least one cycle per second).

4. The structure of claim 1 further characterized in that all but said lirst mentioned two tines vibrate at different resonant frequencies.

5. A tuning fork comprising a plurality of substantially parallel, spaced-apart tines cantilevered from connective means, said plurality of tines comprising at least two fundamental tines having substantially identical physical proportions generally symmetrically disposed about at least one detuned tine having physical proportions such that its resonant vibration frequency is different from that of said fundamental tines.

References Cited UNITED STATES PATENTS 275,759 4/ 1883 Fischer 84-,409 2,601,801 7/1952 Langloys 11-457 FOREIGN PATENTS 416,578 7/ 1925 Germany.

RICHARD B. WILKINSON, Primary Examiner.

LAWRENCE FRANKLIN, Assistant Examiner. 

